The marine environment provides adaptive conditions for many organisms, such as algae, shellfish, mussels, sponges, corals, and barnacles. There is a range of algae in Pakistan’s coastal waters, but, unfortunately, they are not used and are wasted. Efficient use of a valuable natural resource that can increase the efficiency of agricultural operations. Algae are abundant and easily found in a wet environment, either in seawater or freshwater. The seaweed and its products are extensively used in crops cultivation to enhance production systems due to many plant-growth-promoting compounds. It has been traditionally used for the fertilization of the fields since the ancient world. Some seaweeds and auxins, a plant hormone responsible for the vegetative growth and auxin-like compounds, have been found. Algae and their associated compounds can support the onset of seed germination and plant root growth, which applies to temperature, resistance to abiotic stress, and improves plants’ ability to absorb nutrients.

Soil pollution with heavy metals is continuously expanding with the rapid development of industrialisation and agriculture. The current study was aimed to determine the skewed nature and spatial distribution of soil heavy metals pollution in southern areas of Khyber Pakhtunkhawa. Fifty four soil samples were collected from the selected sites in southern districts and analysed for various soil physico-chemical and elemental concentrations. Various metals content, i.e. (Pb, Cd, Ni, Cr) was determined after acid digested through atomic absorption spectrophotometry. Results of the metals content in soil samples showed maximum values Pb (46.38), Cd(6.74), Ni(45.58), Cr(58.08) mg/kg, bluk density 1.46 g/cm³ and lowest pH value 6.53 for Lakki cement factory (LCF) site. Other parameters like soil electrical conductivity, total dissolved solids, percent porosity and soil urease activity also indicated higher values, i.e. 504 µs/cm, 250 mg/lit, 66% and 440.50 respectively. Positive Pearson correlation was found between metals concentration and soil physico-chemical properties except percent porosity and bulk density exhibited negative correlation. The multivariate statistical analysis of the data formed principal component that accounted for a total variance of 71.1%, on the basis of which metal contamination is traced to both geogenic and anthropogenic sources. Spatial distribution of the metals concentration showed higher concentration of Cd, Cr, Ni in Lakki cement factory (LCF) soil except Pb content that was observed maximum in Indus highway Karak (IHK) soil samples. Geoamccumulation index (I_geo) of the samples sites showed moderate contamination for studied metals with some uncontaminated sites showing a value of I_geo> 0. The study concludes a baseline data for metals concentration in the area, which can be used as a beacon for various strategic plannings regarding soil resource management in order to address the metals related health issues and environmental pollution.

The sustainable development of modern agriculture faces many obstacles, including biodiversity loss and environment and soil degradation. Algae possess the ability to fix carbon through photosynthesis and produce enormous biomass. The potential use of algae in bio-fertilizers, nutrient recycling, crop stimulants against abiotic stresses, and bio-control agent against plant pests provides a way forward for sustainable agriculture development. This chapter summarizes the use of algae in agriculture ranging from bio-fertilizers to crop stimulants. It is expected that the integration of algae in inputs will transform modern agriculture into a more environmentally benign and resource-efficient system, hence making it more productive. Request access from your librarian to read this chapter's full text.